김경택 교수

A method to generate and control the permeability of polymersome membranes using mixtures of amphiphilic and stimuli-responsive boronic acid-containing block copolymers is reported. The latter block copolymers form phase-separated domains in the polymersomes, which can be dissolved by increasing the pH of the medium or by introducing sugar molecules that covalently bind to the boronic acid moieties.

We report here a controllable shape transformation of polymer vesicles (polymersomes) constructed from block copolymers of which the hydrophobic part is a high-molecular-weight glassy segment. Control over the shape transformation is obtained by kinetic manipulation of the phase behavior of this glassy hydrophobic segment. Kinetic manipulation of the phase behavior of polymer membranes allows for different shapes of polymersomes to be captured at specific times, which directly translates into ph

We highlight recent advances in the synthesis of nanocarriers and nanoreactors from synthetic and biological building blocks with emphasis on the stimulus-responsive regulation of their function.

We present the first detailed report of the synthesis of Wulff-type styrenic monomers and their polymerization by radical addition-fragmentation chain transfer (RAFT) methods. The resulting polymers and block copolymers exhibit sugar-responsive solubilization in aqueous buffer solutions (pH = 7.4-7.8) in the presence of monosaccharides such as D-fructose and D-glucose.

Thermoreversible gelation of diblock copolymers of a helical polypeptide, poly(γ-benzyl-L-glutamate) and random-coil polymers such as polyferrocenylsilanes in dilute solution has been discovered (see picture). A new mechanism for self-assembly of block copolymers of helical polypeptides is proposed.

Block copolymers (BCPs) have been indispensable building blocks to create a range of soft nanostructures including discrete particulates (micelles and vesicles) and periodic structures via spontaneous assembly in bulk and in solution. The size, shape, and phase of these structures can be controlled by the rational design of the molecular structure of building blocks based on the structural analogy of BCPs to lipids and small molecule surfactants. Inverse bicontinuous cubic mesophases of polymers

We report here the synthesis of cyclic polymers and block copolymers consisting of discrete numbers of repeating units without linear contaminants. The synthesis utilizes the intramolecular cyclization of end-functionalized poly(<i>rac</i>-lactide) (PLA) and its block copolymers with as many as 512 lactic acid units (37 kDa), synthesized by the iterative linear convergence of orthogonally protected building blocks. By exploiting the change in hydrodynamic volume upon cyclization of the linear po

We report here a strategy for influencing the phase and lattice of the inverse mesophases of a single branched-linear block copolymer (BCP) in solution which does not require changing the structure of the BCP. The phase of the self-assembled structures of the block copolymer can be controlled ranging from bilayer structures of positive curvature (polymersomes) to inverse mesophases (triply periodic minimal surfaces and inverse hexagonal structures) by adjusting the solvent used for self-assembly

Solution self-assembly of block copolymers into inverse bicontinuous cubic mesophases is a promising new approach for creating porous polymer films and monoliths with highly organized bicontinuous mesoporous networks. Here we report the direct self-assembly of block copolymers with branched hydrophilic blocks into large monoliths consisting of the inverse bicontinuous cubic structures of the block copolymer bilayer. We suggest a facile and scalable method of solution self-assembly by diffusion o

Bottlebrush block copolymers (BBCPs) exhibit a distinct brush-like topology, which extends their conformations and, consequently, limits chain–chain entanglement in bulk forms and in concentrated solutions. These characteristics make them attractive building blocks to create well-defined nanostructures with large periodicities by self-assembly. However, self-assembly of BBCPs into periodic nanostructures in a dilute solution has rarely been studied. Here, we report the solution self-assembly of

Accelerated and parallel synthesis of sequence-defined polymers is an utmost challenge for realizing ultrahigh-density storage of digital information in molecular media. Here, we report step-economical synthesis of sequence-defined poly(l-lactic-<i>co</i>-glycolic acid)s (PLGAs) using continuous flow chemistry. A reactor performed the programmed coupling of the 2-bit storing building blocks to generate a library of their permutations in a single continuous flow, followed by their sequential conv

The synthesis and structural characterization of the first organometallic-polypeptide block copolymers, poly(ferrocenyldimethylsilane)-b-poly-(??-benzyl-L-glutamate) was performed. The deprotection of the material to form the water-soluble organometallic-polypeptide block copolymers, PFS-b-poly(L-glutamic acid) (PFS-b-PGA) was also discussed. The macroinitiator PFS-NH2 was used for the ROP of ??-benzyl-L-glutamate NCA to obtain the organometallic-peptide block copolymers. The 1H NMR of the purif

Monodisperse polymers composed of a discrete number of repeating units have attracted considerable interest as model systems to investigate the behavior of polymers having chemical structures without statistical distribution. Herein, we report the crystallization-driven self-assembly (CDSA) of block copolymers (BCPs) built with monodisperse poly(lactic acid) (MPLA) composed of enantiomeric repeating units connected in a defined sequence and poly(ethylene glycol) (PEG). The morphology of self-ass

Dendritic-helical diblock copolypeptides, dendritic poly(-lysine)--poly(γ-benzyl--glutamate) (PBLG-Lys) were synthesized up to 4th generation of dendritic poly(-lysine). PBLG was synthesized by conventional ring-opening polymerization of γ-benzyl--glutamate--carboxyanhydride with heptyl amine as an initiator. The -terminus of this PBLG was used for further coupling reactions with ,-bis(-butoxycarbonyl)--lysine pentafluorophenylester. These block copolypeptides possess well-defined 3-D structures

New macromolecular self-assembling building blocks, dendron-helical polypeptide copolymers, have been synthesized; these materials possess a well-defined 3-D shape and self-assemble in solution to form nanoribbon and lyotropic liquid crystalline phases.